Yet Another Command Line Experiments.

The not so short guide to compile Android Jelly Bean 4.1.1_r4 for the Galaxy Nexus



Back to the beginning of this year, I succeded in compiling ICS AOSP 4.0.3_r1 for the Galaxy Nexus. At that time, I didn’t have much time to post a full entry on the whole compilation process (including the different hacks needed to get a fully functional ROM).

With the Jelly Bean AOSP release and my third ROM compilation, I’ve succesfully compiled 4.1 back in July. Now we have 4.1.1_r4 and it’s due time for me to document the process using Debian GNU/Linux.

Without the Android Open Source Project, nothing has been possible and the website clearly describes how to proceed to get the code and compile it for a supported target. I will not rewrite the provided documentation but I’d rather provide a guide on how I have obtained my own ROM. Feel free to review and I will update accordingly.

DISCLAIMER: Please do not do anything described in this post if you have no idea of what you are doing! I will not be held responsible for bricking your phone or invalidate your device warranty! Do not forget to backup your data before doing anything since any issue may involve a factory reset!

My first advices are:

  • Browse the AOSP website
  • Read that whole post a first time before doing anything
  • Unlock your bootloader
  • Flash clockworkmod
  • Backup your ROM

Get the Android Open Source Project code

Follow the instructions given by the “Downloading the Source” section of the AOSP website.

$ mkdir ~/foo/bar/android
$ cd ~/foo/bar/android
$ repo init -u -b android-4.1.1_r4
$ repo sync

These commands apply even to an existing Android source tree but you will need to clean up your source tree from a previous build by using:

$ make clobber

That’s the first step to get a JRO03L rom…

Prerequisites for hardware support

To get a fully functional rom, you need to get the hardware support. Unfortunately, we only have access to the binaries distributed for the JRO03H rom Galaxy Nexus (GSM/HSPA+) binaries for Android 4.1.1 (JRO03H):

$ mkdir ~/foo/android_prereq
$ cd ~/foo/android_prereq
$ export BINARIES="broadcom-maguro-jro03h-4cc54d09,imgtec-maguro-jro03h-827bcb4c,invensense-maguro-jro03h-682067a4,samsung-maguro-jro03h-0655880b"
$ curl -# -OOOO{${BINARIES}}.tgz
$ md5sum *
b05a41ed3096c5f19ebc5b172f034e93  broadcom-maguro-jro03h-4cc54d09.tgz
cabedd37a42a9cbe47e1702a122421e0  imgtec-maguro-jro03h-827bcb4c.tgz
c575cc3a712ef61d2ef5eb5e08f054eb  invensense-maguro-jro03h-682067a4.tgz
cda04a52492ee9762196248abb2834d1  samsung-maguro-jro03h-0655880b.tgz
$ unset BINARIES

Retrieve the installation scripts:

$ cd ~/foo/bar/android
$ find ~/foo/android_prereq -maxdepth 1 -type f -exec tar xzvf {} \;

Finally, it is the time to extract the binaries to the source tree:

$ for i in `ls -1 extract-*`; do ./$i; done;

DISCLAIMER: You must accept the terms of each of the licences before going further!

Initialize the build environment

In the past, I’ve always compiled a userdebug rom. Now, I would like to get a user rom since I’m happy with an unthemed and odexed rom.

$ . build/
$ lunch full_maguro-user


If you prefer a userdebug build, just do:

$ . build/
$ lunch full_maguro-userdebug


Flash the bootloader and the baseband firmware to the latest versions available

Get the latest factory image “yakju” for Galaxy Nexus “maguro” (GSM/HSPA+) JR003C

$ mkdir ~/foo/android_prereq/jro03c
$ cd ~/foo/android_prereq/jro03c
$ curl -#O

We will need fastboot to flash images to the device. More over, since it’s the time to compile some host utilities, we take the opportunity to get adb (necessary to interact with the device for debug purposes) and the simg2img (usefull to convert a sparse image file to a raw image file).

$ cd ~/foo/bar/android
$ make fastboot adb simg2img

The resulting host binaries could be found in the ~/foo/bar/android/out/host/linux-x86/bin directory.

If your bootloader is not already unlocked, you will need to boot in fastboot mode:

Press and hold both Volume Up and Volume Down, then press and hold Power.

AOSP Website Booting Into Fastboot Mode Section for the Maguro Device

We define a linux local alias to simplify the use of the brand new fastboot (using the _aosp suffix).

$ alias fastboot_aosp=/home/renaud/git/android_ics/out/host/linux-x86/bin/fastboot

Let’s get and flash the bootloader and the baseband from the JRO03C factory to the actual device:

$ cd ~/foo/android_prereq
$ tar xzvf yakju-jro03c-factory-3174c1e5.tgz
$ tar xzf yakju-jro03c-factory-3174c1e5.tgz
$ cd yakju-jro03c
$ fastboot_aosp flash bootloader bootloader-maguro-primelc03.img
$ fastboot reboot-bootloader
$ fastboot flash radio radio-maguro-i9250xxlf1.img
$ fastboot reboot-bootloader

The bootloader now display:


Getting root or injecting su and Superuser to the source tree

Make a backup of the original su source:

$ mkdir ~/android_backup
$ cp -rf ~/foo/bar/android/system/extras/su .

Then inject ChainsDD/su-binary using my slightly modified fork:

$ cd ~/foo/bar/android/system/extras
$ git clone su

I want the su binary to be compiled in the very same time of the full AOSP build. As a consequence, I have modified the original file by setting LOCAL_MODULE_TAGS := optional and adding the su module to PRODUCT_PACKAGES into the build/target/product/ file to force the inclusion.

I want to have the ChainsDD/Superuser apk included into the build as a system app:

$ cd ~/foo/bar/android/packages/apps
$ git clone

and add Superuser to PRODUCT_PACKAGES into the build/target/product/

You will need to generate your own certificate for Superuser using:

$ cd ~/foo/bar/android
$ development/tools/make_key superuser '/C=US/ST=State/L=Location/O=YourOrg/OU=WhateverYouWant/CN=WhateverYouWant/'
$ mv superuser.pk8 build/target/product/security/

If superuser.pk8 is not there, the compilation process will fail… Don’t go too far away from your computer since the Superuser compilation will require your password to get the build done.

Time to compile

You’ll need to read the building section of the AOSP website as a prerequisite.

After setting ccache to fit with your resources, just do:

$ cd ~/foo/bar/android
$ make -j4

You normally end up with flashable images located in out/target/product/maguro/. The whole compilation process took a very long time on my machine… so be it and be warned!

Flash the images to the devices

Assuming the fastboot_aosp alias is defined and the battery of your device is decently charged, just flash the whole system with:

$ fastboot_aosp flashall

If you upgrade from a previous Android version, you should wipe your data using the -w switch:

$ fastboot_aosp -w flashall

The whole flashing process took about 1 min. to finish on rebooting the device. Congrats! But wait, this is not the end…

If you have clockworkmod installed on your recovery partition, flashall will overwrite it with the nominal android recovery.

Flash or reflash clockworkmod recovery (for later use)

The clockworkmod recovery enable us to backup and/or restore our ROMs and apply zip update files.

Get the Koushik Dutta’s clockworkmod recovery (direct link ATTOW).

Some hardware parts are not properly supported!

If you test the gps or the camera, you certainly are already grumbling…

Some binaries are distributed by Google, some aren’t and since the famous have been suppressed from this release, you will have to hunt down some missing libraries. You’ll need to play with find/sort/diff combos to figure out which one are needed.

OK, but on which reference data? Remember the simg2img host compilation? Time to use it…

Some inoffensive linux commands:

$ simg2img system.img system.img.raw
$ mkdir mnt-point
$ sudo mount -t ext4 -o loop system.img.raw mnt-point/

Please read the following section before hunting down the missing files…

Where are my GApps!

The GApps are not-so-useless on Android but they are not Open Source and therefore not distributed by Google AFAIK… Considering the situation, Google seems flexible, up to now, about the various gapps packagings out there…

The short version: Go get a gapps update file on ( ATTOW). Use adb to put that file on the device storage, reboot to clockworkmod and apply…

You should (in not must) locally unzip the file to see what’s into it before flashing and before processing the previous section…


That post is more a personal log than a real guide and although some parts could be automated, the manual toying is a full learning experience!

Have fun!